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| author | Christian Borntraeger <borntraeger@de.ibm.com> | 2008-04-17 07:46:30 +0200 |
|---|---|---|
| committer | Heiko Carstens <heiko.carstens@de.ibm.com> | 2008-04-17 07:47:07 +0200 |
| commit | 9e74a6b8983c2653dd2a6f51e634efa281e95d59 (patch) | |
| tree | 46a6e3c866a3b7642c6176a9c0ef636267196c0f /arch/s390 | |
| parent | 1a5debaaace41f1e91014332e6eedde4499e5638 (diff) | |
| download | linux-9e74a6b8983c2653dd2a6f51e634efa281e95d59.tar.bz2 | |
[S390] kernel: show last breaking-event-address on oops
Newer s390 models have a breaking-event-address-recording register.
Each time an instruction causes a break in the sequential instruction
execution, the address is saved in that hardware register. On a program
interrupt the address is copied to the lowcore address 272-279, which
makes it software accessible.
This patch changes the program check handler and the stack overflow
checker to copy the value into the pt_regs argument.
The oops output is enhanced to show the last known breaking address.
It might give additional information if the stack trace is corrupted.
The feature is only available on 64 bit.
The new oops output looks like:
[---------snip----------]
Modules linked in: vmcp sunrpc qeth_l2 dm_mod qeth ccwgroup
CPU: 2 Not tainted 2.6.24zlive-host #8
Process modprobe (pid: 4788, task: 00000000bf3d8718, ksp: 00000000b2b0b8e0)
Krnl PSW : 0704200180000000 000003e000020028 (vmcp_init+0x28/0xe4 [vmcp])
R:0 T:1 IO:1 EX:1 Key:0 M:1 W:0 P:0 AS:0 CC:2 PM:0 EA:3
Krnl GPRS: 0000000004000002 000003e000020000 0000000000000000 0000000000000001
000000000015734c ffffffffffffffff 000003e0000b3b00 0000000000000000
000003e00007ca30 00000000b5bb5d40 00000000b5bb5800 000003e0000b3b00
000003e0000a2000 00000000003ecf50 00000000b2b0bd50 00000000b2b0bcb0
Krnl Code: 000003e000020018: c0c000040ff4 larl %r12,3e0000a2000
000003e00002001e: e3e0f0000024 stg %r14,0(%r15)
000003e000020024: a7f40001 brc 15,3e000020026
>000003e000020028: e310c0100004 lg %r1,16(%r12)
000003e00002002e: c020000413dc larl %r2,3e0000a27e6
000003e000020034: c0a00004aee6 larl %r10,3e0000b5e00
000003e00002003a: a7490001 lghi %r4,1
000003e00002003e: a75900f0 lghi %r5,240
Call Trace:
([<000000000014b300>] blocking_notifier_call_chain+0x2c/0x40)
[<000000000015735c>] sys_init_module+0x19d8/0x1b08
[<0000000000110afc>] sysc_noemu+0x10/0x16
[<000002000011cda2>] 0x2000011cda2
Last Breaking-Event-Address:
[<000003e000020024>] vmcp_init+0x24/0xe4 [vmcp]
[---------snip----------]
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Diffstat (limited to 'arch/s390')
| -rw-r--r-- | arch/s390/kernel/entry64.S | 2 | ||||
| -rw-r--r-- | arch/s390/kernel/process.c | 1 | ||||
| -rw-r--r-- | arch/s390/kernel/traps.c | 10 |
3 files changed, 12 insertions, 1 deletions
diff --git a/arch/s390/kernel/entry64.S b/arch/s390/kernel/entry64.S index efde6e178f6c..cd959c0b2e16 100644 --- a/arch/s390/kernel/entry64.S +++ b/arch/s390/kernel/entry64.S @@ -475,6 +475,7 @@ pgm_check_handler: pgm_no_vtime: #endif lg %r9,__LC_THREAD_INFO # load pointer to thread_info struct + mvc SP_ARGS(8,%r15),__LC_LAST_BREAK TRACE_IRQS_OFF lgf %r3,__LC_PGM_ILC # load program interruption code lghi %r8,0x7f @@ -847,6 +848,7 @@ stack_overflow: je 0f la %r1,__LC_SAVE_AREA+32 0: mvc SP_R12(32,%r15),0(%r1) # move %r12-%r15 to stack + mvc SP_ARGS(8,%r15),__LC_LAST_BREAK xc __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15) # clear back chain la %r2,SP_PTREGS(%r15) # load pt_regs jg kernel_stack_overflow diff --git a/arch/s390/kernel/process.c b/arch/s390/kernel/process.c index dbefd0db395f..c1aff194141d 100644 --- a/arch/s390/kernel/process.c +++ b/arch/s390/kernel/process.c @@ -195,6 +195,7 @@ void show_regs(struct pt_regs *regs) /* Show stack backtrace if pt_regs is from kernel mode */ if (!(regs->psw.mask & PSW_MASK_PSTATE)) show_trace(NULL, (unsigned long *) regs->gprs[15]); + show_last_breaking_event(regs); } extern void kernel_thread_starter(void); diff --git a/arch/s390/kernel/traps.c b/arch/s390/kernel/traps.c index b3524134f213..57b607b61100 100644 --- a/arch/s390/kernel/traps.c +++ b/arch/s390/kernel/traps.c @@ -134,7 +134,6 @@ void show_trace(struct task_struct *task, unsigned long *stack) else __show_trace(sp, S390_lowcore.thread_info, S390_lowcore.thread_info + THREAD_SIZE); - printk("\n"); if (!task) task = current; debug_show_held_locks(task); @@ -162,6 +161,15 @@ void show_stack(struct task_struct *task, unsigned long *sp) show_trace(task, sp); } +#ifdef CONFIG_64BIT +void show_last_breaking_event(struct pt_regs *regs) +{ + printk("Last Breaking-Event-Address:\n"); + printk(" [<%016lx>] ", regs->args[0] & PSW_ADDR_INSN); + print_symbol("%s\n", regs->args[0] & PSW_ADDR_INSN); +} +#endif + /* * The architecture-independent dump_stack generator */ |